The objectives of the two projects included in this project grant are (1) to develop and evaluate new methods for studying pulmonary function in infants and children, (2) to study the interrelationships between cardiovascular and pulmonary function in patients with congenital heart disease and obstructive pulmonary disease, particularly in the month to five year age range, (3) to continue long term studies of programs and measures for the provision of prophylactic and therapeutic treatment for cystic fibrosis, (4) to develop clinical, bacteriologic, roentgenologic, biochemical, pulmonary function test and cardiologic methods for objectively studying pediatric patients with chronic obstructive pulmonary disease and (5) to utilize all of these objective methods to assist in developing and evaluating both new therapeutic measures and comprehensive prophylactic treatment programs. Individual therapeutic measures which will specifically be evaluated include inhalation therapy, postural drainage, pulmonary physical therapy, specific antibiotic therapy and drugs which alter autonomic control of pulmonary secretions, mucociliary transport, ventilation and airway defense mechanisms.